Trimming mechanism for sewing machines



June l 1926.

1,586,830 J. R. MoFl-ATT TRIMMING MECHANISM FOR SEWIN-G MACHINES Fil Oct` 13, 1921 3 Sheets-Sheet l ,I ilI J2? n A' J6 Y June" l 1926. 1,586,830

i J. R. MOFFATT l TRIMMING MECHANISM FOR SEWING MACHINES Filed Oct. 13. 1921 MHH .lilllm 5 Sheets-Sheet 2 June l ,1926.

L58630 J. R. MOFFATT TRIMMING MECHANISM FOR SEWING MACHINES Filed 001;. l5, 1921 3 SheetS-Sheeb 5 A mi Patented '.lune 1, 1926.

UNITED` STATES PATENT @ENGEL JAMES P1. MOFFATT, F CHICAGO, ILLINOIS, ASSIGNOR TO UNION SPECIAL MACHINE COMPANY, F CHICAGO, ILLINOIS.. A CORPORATION 0F LLNOS.

TRIMMING- MECIIANISM FOR SEWING MACHINES.

Application filed ctober 13, 1921. Serial No. 507,443.

The invention relates to new and useful improvements in trimming mechanism for sewing machines, and more particularly a trimming mechanism having a movable trimming blade mounted on the overhanging arm and a stationary ledger blade mounted on the work support.

An object of the invention to provide a trinnning mechanism of the above character with interchangeable ledger blades and means whereby the position of the movable blade on the supporting means may be shifted transversely of the path of reciprocation of the needle to position the movable trimming blade for proper cooperative action with the selected ledger blade.

ii further object of the invention is to provide a trimming mechanism wherein the movable trimming blade is carried by a pivoted support `and is ylieldingly pressed into engagement with an adjustable stop,` so that the pressure of the blade against the ledger blade may be varied.

further object of the invention is to provide a support for the movable trimming blade of the above character, wherein the pivotal support is so disposed relative to the means for shift-ing the blade laterally that the angle of reciprocation of the blade may be vaied within certain limits.

'llhese and other objects will in part be obvious and will in part be hereinafter more fully disclosed.

ln` the drawings which show by way of illustration one embodiment of the inventioni Figure l is a view partly in front elevation and partly in vertical section, showing a sewing machine embodying my improvements;

Figure 2 is a view partly in fro-nt end elevation and partly in vertical section of the same;

iiliguro i?) is a view partly in plan and partly in section of the forward end of the wor support and the parts immediately above the same;

Figure l is a perspective view of the supporting means for the movable trim-mer;

Figure 5 is an enlarged vertical sectional view on the line 5 5 of Figure li;

Figure 6 isa sectional view on the line 6 6 of Fig. 5.

-The invention isdirected to a trimming mechanism of the type shown in the patent granted to Mather, Holland t l/Voodward November 2,1897, No. 592,806. rllhe trimming mechanism of said patent consists of a stationary ledger blade mounted on the work support and a movable trimming blade mounted on the overhanging arm. This movable trimming blade is recip-ro'cated in a vertical plane. The needle bar is Carried by a support capable of being shifted transversely so that the position of the line of stitching may be shifted toward or from the trimming blade within a limited range of adjustment. When it is desirechhowever, to get widerranges of adjustment, so that the trin'nning of the edge will be farther from the line of stitching than can be accomplished by adjusting the position of the needle bar, then interchangeable supports for the movable trimming blade are provided so that the movable blade may be set at different distances from the center' of the needle hole in the throat plate and interchangeable throat plates are provided with ledger blades properly positioned to co-operate with the trimmer blade in its. shifted positions.

kThe present invention is directed to the support for the movable trimming blade which permits the movable trimming blade to be shifted without removing and replacing the-support for the trimming blade as heretofore.

ln the broad aspect of the invention, the movable trimming blade is vcarried by a shiftable head. This shiftable head is positively moved so `as to shift the position of the movable trimming blade transversely of the line of reciprocation of the needle. Locking means is provided for holding the shiftable head in its various adjusted positions. Thus it is that the trimming blade may be readily set to co-operate with the properly selected ledger blade so as to trim the desired distance from the line ofstitehing. The trimming blade is mounted direectly on a pivoted support carried by the shifta-ble 'head and this pivotal support is yieldingly swung soas to press the movable trimming blade with a yieldingforce against the ledger blade. A stop screw is provided to limit this movement of the movable blade toward the ledger blade. Means is also provided for varying the tension of the spring and an adjustable screw is so Set' that the pressure ofthe upper lmifeor lll) movable bladeagainst the lower knife or ledger blade may be increased or decreased. Through the combined adjustments of the shiftable head and the pivotal support the angle of the movable blade to the. vertical may be adjusted.

Referring more in detail to the drawings, l have shown the invention applied to a sewing machine Which includes a Work sup port 1, an overhanging arm Q, carrying a needle bar gate 3, in which a needle bar el reciprocates. Said needle bar carries a needle The needle bar gate is pivoted'at t3 to the overhanging arm. Projecting laterally from the needle bar gate is an arm T which is provided with a suitable recess adapted to engage a cam or eccentric on the shaft S. and this shaft 8 is adapted to bc shifted by means of an arm 9 and the amount of movement Which may be imparted to the shaft S is limited by a pin 10 adapted to enstop screws 11 and 12, disposed on op,- posite sides of the pin.

(3o-operating with the needle beneath the vvork support is a looper 13. Said looper is carried by a looper support 1l, pivoted at 15 to a looper rocker 1G. The material is fed across the Work support by means of a feed dog 17, carried by a feed bar 18. which is attached to a feed rocker 19. rl`his feed dog liis located beneath the Work support. Vlfbe parts above described are all shoivn and described in detail in the patent to lluther et al. No. 592.2306, above referred to, and further description of these parts is not tl'iouglit necessary.

Cri-operating with the feed dog 17 above the material is a feed dog 20. This feed dog 2O is carried by a feed bar 21 Which is moved back and forth by the rocker 19 and said feed bar is raised and lowered by means of an eccentric on the main shaft 23. The material held on the Work support by means of a presser foot 524:5 carried by a presser bar 25.

The Work support 1 is provided with a throat plate 26. Said throatplate :26 carries a bar 27, formedivith a needle hole f2.9 and a recess portion forming a ledger blade 30 on said bar 27. (l0-operating. with this station ary ledger blade on the throat plate is a movable triinmingblade 3l. The Work support 1 is provided with a rece-ss in Which is located a spring-pressed member which bears lightly against the 'trimming blade and closes the opening in the Work support around the trimming blade. The movable trimming blader 31 is rigidly clamped to a pivotal support 3a. Said support 3l is pivotally carried by a shiftable head 235.l A pivot pin 36 passes through the support into the shiftable head 35, see 6. Said pivotal-support is provided With` a projecting sleeve'l 3T- Which is.` formedpintegral. with the pivot-alA support. and" increases the' bearing suppertitherefor'. The pinfpasses through 1,5e6,seo

this projecting sleeve. The movable blade 31 is secured to the pivotaly support 3l by means of a screiv 38 which passes through an elongated slot 39 in the blade. This elongated slot permits the blade to beraised and lowered so as to be br'ouglit into proper cooperative action with the ledger blade on the throat plate of the machine. The shiftable head 35 is provided With a recess ivhich enj res a lin Ll() on the bracket 41. This fin and recess are so located that the shiftable head may be movedv longitudinally thereof and transversely of the line of reciprocation of the needle. The bracketv l1 is provided with a recess lQin which is located an adjuting screiv Said adjusting screiv 43 is threaded into the bracket. Said adjustscrew is provided with a collar elet, spaced slightly from the head of the screw and the shiftable head 35 is formed With suitable recesses to receive the head of the Screw and the collar 441-, so that When the screw is turned the shiftable head' Will be positively moved on the bracket 41 toward and from the line of reciprocation of the needle. Saidv shifta-ble head is provided With a slot l5 through which a screw f6 passes and this screiv is threaded into the bracket Ll1 and serves to lock the shiftable head in adjusted positions and prevents the same from creeping one Way or another by accident-al turning of the screw 43.

rihe pivot al support for the trimming blade is swung so as to press the movable blade against the ledger blade by means of a spring el?. Said spring fl? bears at its loiver end on an arm llelprojecting loutwardly from the support Srl. i This spring` is located in a sleeve which is capable of being adjusted iu an arm 50, carriedby the shiftable head. Through the adjustment of this sleeve the pressure of the spring on the arm d8 may be adjusted. il limitingl screw 51 is carried by an arm 52 projecting outwardly from the shiftable head 35, and serves to limit the doivnivard movement of the arm d8. This scrciv hoiveyer is so positioned as to allow the movable trin'nning blade to bear vvith yielding. pressure against the ledger blate and this pr rrure may be increased or decreased by varying;- thetension of the spring l?.

The bracket Ll1 forms a part of the yoke 5S. The upper member 5l of this yoke, together with the bracket member `r`l1, slide vertically on the presser bar and the yoke is rcciprocated by means of a link 55k which is connected to an arm 56 carried by the shaft 57. The shaft 5T is oseillated by means of an arm 58` to Which a link 59 is attached. The link 59 is reciprocated by means ofv a yoke-cooperating With an eccentric on the main shaft 23 and in the ina-nner fully set forth. in the Mather etV al4 patent, above reierifed to;

lllounted on the work support l is a stripr detlector 60. The material, as shown in Fig, il, is indicated at F and a trimmed oli strip at f, and it is this trimmed oit1 strip that engages the strip delector and is diverted to one side.

W hen it is desired to shift the position otl the line of stitching slightly -from the edge which is being trimmed, the needle bar may` be moved transversely through the arm and the parts associated therewith and after the manner described in the Muther et al. patent. rllhe amount of shift, however, given to the needle is limited. vWhen it is desired to increase 'to a considerable extent the distance between the line oit stitching and the trimmed edge a new throat plate or ledger supporting bar is substituted, wherein the ledger blade is made a different distance from the needle.` The shittable head is then moved transversely to bring the movable trimming blade `into proper cooperation with the newly selected ledger blade. lt will, therefore, be noted that I have provided means for supporting the movable blade whereby it may be shifted transversely of the line of reciprocation ot the needle to properly position the same for interchangeable throat plates having ledger blades at diiierent distances from the line of reciprocation of the needle. Furthermore, the movable blade is carried by a pivotal support and this pivotal support is spring pressed so as to yieldingly torce the movable blade laterally against the ledger blade. By varying the tension of the spring the pressure ot the movable blade against the ledger blade may be increased or decreased asdesired. By shifting the head carrying the pivotal support and the limiting screw 5l the movable blade may be set at slight angle to its path of reciprocation.

It has been 'found from practice that it the movable blade be set at a very slight angle, possibly hali1 a degree or thereabouts, to the. vertical better trimming results will be accomplished, yand this setting of the trimming blade is permitted by the mechanism above described.

lt is obvious that minor changes in the details otl construction and the arrangement ot' the parts may be made without departing from the spirit of the invent-ion as set iorth in the appended claims.

Having thus described my invention, what l claim as new and desire to secure by Letters Patent ot the United States is:

1. The combination with stitch forming mechanism including a reciprocating needle, of a trimming mechanism comprising a stationary ledger blade, a movable blade cooperating` therewith, a reciprocating support for said movable blade including devices whereby the blade is yieldingly forced laterally against the stationary ledger blade, and

vthe ledger blade, means for varyin means for bodily shifting said support tor the movable blade on its reciprocating .means in a direction at right angles to the line` ot reciprocationof said blade supporting means so that said blade maybe positioned lor cooperation with stationary trimming blades of different widths 2. The combination with vstitch :forming mecha-nismv including a reciprocating needle, oi" a trimming mechanism comprising a stationary ledger blade, a movable blade co-operating therewith, a reciprocating support tor said movable blade including devices whereby the blade is yieldingly forced laterally against the stationary ledger blade, and means for positively shitting said support 'for the movable blade on its recilirocating means so that said blade may be positioned i'or co-operation with stationar f trimming blades ot different widths, and locking means tor locking the shiftable support in adjusted positions.

3. The combination with stitch forming mechanism including a reciprocating needle, ot a trimming mechanism comprising a stationary' ledger blade, a movable blade cooperating therewith, apivotal support for said movable trimming blade, a shittable head on which said pivotal support is mounted, a spring for turning said pivotal support to press the movable blade against the ledger blade, and means Jfor varying the tension of said spring.

a. The combination with stitch forming mechanism including` a reciprocating needle, o't` a trimming mechanism 'comprising' a stationary ledger blade, a movable blade cooperating therewith, a pivotal support for said `movable trimming blade, a shiftable head on which said pivotal support is mounted, a spring for turning said pivotal support to press the movable blade against g the tension of said spring, and a limiting screw for limiting the movement oit the pivotal. support.

5. The combination with stitch forming mechanism including a reciprocating needle, of a trimming mechanism comprising a stationary ledger blade, a movable blade cooperating therewith, a pivotal support .tor said movable trimming blade, a shittable hea-d on which said pivotal support is mounted., av spring for turning said pivotal support'to press the movable blade against the ledger blade, means for varying the tension ot said spring. and means for positively n'ioving the shiitable head toward and from the line of reciprocation of the needle.

6. The combination with stitch forming mechanism including a reciprocating needle, of a trimming mechanism comprising a stationary ledger blade, a movable blade cooperating therewith, a pivot-al support for said movable trimming blade, a shitta-blc head on which said pivotal supportv is mounted, a spring for turning said pivotal support to press the movable blade against the ledger blade, means tor varying the tension oit said spring, means for positively moving the shii'table head toward and from the line ot reciprocation of the needle, and

means tor locking the shii'table head in adjusted positions.

7. The combination with stitch forming mechanism including a reciprocating needle, of a trimming mechanism. comprising a stationary ledger blade, a movable blade cooperating therewith, a pivotal support on which said blade is mounted, a shiftable head carrying said pivotal support, a vertically reciprocating bracket carrying said shittable head, said shiftable head havingv a ribbed connection with the bracket permitting the headl to be moved horizontally toward and from the needle, an adjustable screw carried by the bracketand having connection with said shiittable head for positively moving` the head toward and from the needle, a spring lor turning said pivotal support on the shittable head to yieldingly press thev movable blade against theledger blade,V and. means whereby the tension ot said spring may be varied.

8. rlhe combination with stitch forming mechanism including a reciprocating needle, ot' a trimming mechanism comprising a stationary ledger blade,.a movable blade cooperating therewith, a pivotal support on which said. movable blade is mounted, a

shii'table head carryingsaid pivotal support, a vertically reciprocating bracket carrying said shittable head, said shittable head having a ribbed connection with the bracket permitting the head tobe moved horizontally toward and from the needle, an adjustablescrew carried by the bracket and having connection with said shittable head tor positively moving the head toward and from the needle, a spring for. turning: said pivotal support on the shiftable head to yieldingly pressl the movable blade against the ledger blade, means whereby the tension of said spring may be varied, and a limiting screw for limiting the movement ot' the movable blade in a direction toward the ledger blade.

il. The combination with stitch forming mechanism including a reciprocating needle, o'l' a trimming mechanism comprising a stationary ledger blade, amovable blade cooperating therewith, a pivotal support, means for connecting said movable blade to assenso said pivotal support whereby'said blade may be adjusted longitudinally on saidpivotal support, a shil'table head on which said pivotal. support is mounted, whereby said blade swings in a vertical plane toward and from the ledger blade, a spring engaging said pivotal support for yieldingly pressing the movable blade against the ledger blade, said shi'ttable head being capable of adjustment in a horizontal direction toward and from the line oi'l reciprocation oi' the needle.

1G. The combination with stitch forming mechanism including a reciprocating needle, ot a trimming mechanism comprising a stationary ledger blade, a movable blade cooperating therewith, a pivotal support, means tor connecting said movable blaue to said pivotal support whereby said blade may be adjusted longitudinally on said pivotal support, a s-hi'ltable head on which said pivetal support is mounted, whereby said blade swings in a vertical plane toward and from the ledger blade, a spring engaging said pivotalsupport tor yieldingly pressing the movable blade against the ledger blade, said shiltable` headbeing capable of adjustment in a horizontal direction toward and from the line of reciproca-tion ot' the needle, a vertically reciprocating bracket on which said shittable head is mounted, and a screw for positively moving said head on said bracket.

ll. The combination with stitch 'forming mechanism including a reciprocating neecle, of a trimming mechanism comprising a stationary ledger blade, a movable blade cooperating therewith, a pivotal support, means for connecting said movable blade to said pivotal support whereby said blade may be adjusted longitudinally on said pivotal support, a shiittable head on which said pivotal support is mounted, whereby said blade swings in a vertical plane t-oward and from the ledger blade, a spring engaging said pivotal support for yieldingly pressing the movable blade against the ledger blade, said shittable head being capable of; adjustment in a horizontal direction toward and from the line ot reciprocation of the needle, a vertically reciprocating bracket on which said shitable head is mounted, a screw for positively moving said head on said bracket, and clamping means for positively holding said shiftable head in adjusted positions.

In testimony whereof, I aliix my signature.

JAMES R. MOFFATT. 

